Enormous growth has recently occurred in efforts to adapt HPLC technology to achieve fast, selective, and sensitive separation of large biopolymers, particularly proteins. Most work has focused on improving the solid phase support matrix and solvent desorption process. An entirely different approach involves using a radiofrequency (RF) field to influence protein partitioning during HPLC. We propose to initiate pilot work to determine if the phenomenon of dipole orientation, which occurs to charged macromolecules in the presence of an oscillating RF field, can assist HPLC separation of proteins. By applying an external RF field (1-500 MHz, 10-10,000 V/m) to a HPLC column, RF-induced motion in proteins due to dipole orientation should give rise to unique separations. Since this orientation can be modulated by varing the magnitude of the RF field and its frequency, it should be possible to "tune" RF-assisted HPLC to influence the separation of particular proteins. To test the hypothesis that RF-assisted HPLC will improve the separation of dipolar proteins, a prototype device will be constructed consisting of a ceramic, RF-transparent column to be used with a standard HPLC system, and a RF generating apparatus to apply a RF electric field externally to the column. By comparing the separation of a mixture of highly purified dipolar proteins during RF-assisted HPLC to that for standard HPLC, improvements in speed, sensitivity, and resolution due to specific RF field interactions will be characterized. RF-assisted HPLC has the potential to provide information of biomedical importance, not now available, that is based on the dielectric properties of proteins. For example, alterations in dipole moment (related to charge distribution) and in dielectric relaxation (related to hydrodynamic shape) will be detected by RF-assisted HPLC, and these alterations may reflect biologically important changes in protein structure and function. In addition to this application, RF-assisted HPLC should provide a means to study the general interaction of electromagnetic fields with charged macromolecules. Both applications should significantly broaden the present scope of HPLC analytical capability.